Double-Chamfered HCS Sleeve for Progressive Damper Deceleration

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Solution Overview

Problem

Conventional hydraulic compression stop sleeves in damper assemblies often result in a sudden increase in compressive force during the compression stroke, leading to jarring deceleration and requiring costly, high-strength materials for manufacturing.

Innovation Solution

A tubular hydraulic compression stop sleeve with radially inwardly extending ribs that guide the piston progressively away from the chamfer opening, reducing the sudden increase in compressive force and allowing for manufacturing using a pull broaching process without additional machining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional hydraulic compression stop sleeves are used, then the damper provides compression stop function, but a sudden increase in compressive force occurs causing jarring deceleration

Engineering Contradiction:
Improvesmoothness of decelerationVSAvoidcompressive force increase rate
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The chamfer opening is segmented into multiple chamfer surfaces (first chamfer surface, second chamfer surface, third chamfer surface) that guide the piston through sequential stages. This segmentation divides the single sudden force application into multiple progressive stages, reducing the peak force and creating a smoother deceleration profile.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If conventional hydraulic compression stop sleeves are used, then the structure is simple, but high-strength materials are required increasing manufacturing cost

Engineering Contradiction:
Improvemanufacturing costVSAvoidmaterial strength requirement
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The piston is preliminarily guided by the chamfer surfaces before entering the main compression stop chamber. This preliminary action gradually accelerates the piston and prepares it for compression, preventing sudden force spikes that would require high-strength materials, thereby allowing use of standard materials and reducing manufacturing cost.

Inventive Principle:
Principle #10Preliminary action

3Speed

If the HCS piston enters the HCS sleeve quickly, then the compression stop activates rapidly, but peak force increases causing jarring deceleration

Engineering Contradiction:
Improvepiston entry speedVSAvoidpeak compressive force
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The chamfer surfaces provide beforehand cushioning by gradually accelerating the piston before it enters the compression stop chamber. This preliminary acceleration cushions the subsequent compression action, reducing peak force while maintaining rapid overall response, thereby eliminating jarring deceleration.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively reduces peak force generation and manufacturing costs by creating a progressive increase in damping force, enhancing the damper's performance and manufacturing efficiency.

Implementation Method 1

The HCS body defines a plurality of ribs extending radially inwardly from the chamfer opening and configured to guide the HCS piston apart from the chamfer opening as the HCS piston enters the HCS sleeve

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4421347A1Double chamfered hydraulic compression stop sleeve
Publication Date: 2024.08.28 BEIJING WEST IND CO LTD
  • EP4421347A1 patent drawingFigure 1
  • EP4421347A1 patent drawingFigure 2
  • EP4421347A1 patent drawingFigure 3A~3B

AI summary

A damper assembly with a hydraulic compression stop (HCS) includes a tube defining an interior chamber. The damper assembly also includes a piston assembly slidably disposed in the tube. The piston assembly includes an HCS piston. The HCS piston includes a piston extension with a piston ring disposed thereupon. The damper assembly also includes an HCS sleeve. The HCS sleeve includes an HCS body having a tubular shape and defining a chamfer opening for receiving the HCS piston. The HCS body defines a plurality of ribs extending radially inwardly from the chamfer opening and configured to guide the HCS piston apart from the chamfer opening as the HCS piston enters the HCS sleeve.